Eye Sting Study
determine if a "tear-free" claim can be substantiated
for a product.
Start within 2 weeks of the time the test material is received
assessment by a Board Certified Ophthalmologist
Subjective assessment of pain
subjects are examined by the Ophthalmologist for signs of irritation,
redness and tearing. A trained technician then instills a drop of
the diluted test article into one eye and a competitive control into
the other eye of each subject. Each instillation takes place 5 minutes
apart. After each instillation the subject evaluates the "sting"
of each material based on a 6-point scale. The Ophthalmologist also
examines each subject post-instillation for changes in irritation,
redness and tearing. Range-finding studies with progressive increases
in aqueous concentrations are also available.